Method and communications system for speech communication

ABSTRACT

A method and a communications system for speech communication includes a plurality of workstations and a plurality of radio transmission devices and radio receiving devices. There are control units in the signal path between the workstations and the radio transmission devices and the radio receiving devices. The control units select the speech signals of one of the workstations according to predetermined or predeterminable criteria when there is a simultaneous plurality of operating signals of a plurality of workstations, or overlap the speech signals of a plurality of workstations according to predefined criteria, and transmit the speech signal thus obtained, chosen or overlapped for sending on the radio transmission device. Further, the control units transmit a receiving signal to the workstations connected thereto when the speech signals transmitted from the radio receiving unit are present, and transfer the speech signals to said workstations.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of patent application Ser. No.15/554,140, filed Aug. 28, 2017; which was a § 371 national stage filingof international application No. PCT/AT2016/050031, filed Feb. 18, 2016,which designated the United States; this application also claims thepriority, under 35 U.S.C. § 119, of Austrian patent application No. A50158/2015, filed Feb. 27, 2015; the prior applications are herewithincorporated by reference in their entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The invention relates to a communication system for voice communicationand to a method for a voice communication. Such a communication systemessentially has provision for voice signals and signaling informationPTT/SQU to be able to be transferred from one or more workstations toone or more radio devices and vice versa.

In air traffic control, the size of the communication system and alsothe geographical distribution of the individual components required maybe very different. Small systems, for example tower systems, can consistof a few workstations and a few radio transmission devices and radioreception devices, which are sometimes even accommodated in the samebuilding. Large systems, for example air traffic control centers, canconsist of many hundreds of workstations and correspondingly largenumbers of radio transmission devices and radio reception devices atgeographically distributed sites, any workstation being able tocommunicate with any radio device, depending on the configuration of thecommunication system.

For radio operation, the air traffic controller at the workstation canselect the frequencies required for operation thereof that he wishes totalk on in TX mode and/or listen in on in RX mode. For the transmissionof voice signals, an operator control unit 113, 123, 133 is operated, inparticular a PTT button is pushed, whereupon not only the voice signalspicked up at the workstation but also a PTT signal is transferred to aradio transmission device 51, 52, 53. On the basis of the PTT signal,the RF transmission with the voice signal modulated on is performed atthe radio transmission device 51, 52, 53. When a radio reception device61, 62, 63 receives an RF signal, the demodulated voice signal istransferred together with a received signal SQU to the workstations 11,12, 13. Voice signals that are received on a frequency selected by theworkstation are output on the loudspeaker or in a headset at thisworkstation 11, 12, 13, and the associated received signal SQU isdisplayed on the workstation, e.g. on the graphical user interface.

Additionally, an air traffic controller can couple at least two or morefrequencies to one another, in which case all audio signals that arereceived by a radio reception device 61, 62, 63 associated with one ofthe coupled frequencies are transmitted to the radio transmissiondevices 51, 52, 53 having the other frequencies. Which frequencies anair traffic controller can actually select is dependent on theconfiguration of the workstation 11, 12, 13, this configuration alsobeing able to be swapped.

An example of a communication system that is known from the prior art isdepicted in more detail in FIG. 1. A standard radio workstation 11, 12,13 known from the prior art can have an electronic unit or a PC equippedwith a touch panel for operator control, a microphone 111, 121, 131, anoperator control unit 113, 123, 133 for triggering the PTT signal, aheadset 112, 122, 132 and an optional loudspeaker. Insofar as a radiodevice is under discussion generally, it is understood to mean a radiotransmission device or a radio reception device or a combined radiotransmission and radio reception device.

If each workstation 11, 12, 13 uses a radio transmission device or aradio reception device to set up a direct communication link, the radiotransmission device 51, 52, 53 performs the arbitration for the voicesignal to be transmitted and the radio reception device 61, 62, 63distributes the received voice signals to those workstations 11, 12, 13that have keyed in this frequency. Every signal transfer between aworkstation 11, 12, 13 and a radio device respectively comprises a voicesignal and an associated piece of signaling information PTT or SQU thatis transferred at the same time as the voice signal. For a signaltransfer from a workstation 11, 12, 13 to a radio transmission device,the presence of the voice signal is signaled by an operator controlsignal PTT. The signal transfer between the radio reception device 61,62, 63 and a workstation 11, 12, 13 also comprises a received signal SQUafter the voice signal.

An example of possible communication links between workstations 11, 12,13 and radio transmission device 51, 52, 53 or radio reception device61, 62, 63 is depicted in FIG. 1, each workstation 11, 12, 13 being ableto be allocated any number of radio transmission devices 51, 52, 53 andradio reception devices 61, 62, 63 according to its operationalconfiguration. In the extreme case, this results in an m:n communicationlinks between m workstations 11, 12, 13 and n radio transmission devices51, 52, 53 or radio reception devices 61, 62, 63. This results in theproblem that when a workstation 11, 12, 13 transmits a voice signal to nradio transmission devices 51, 52, 53 simultaneously, n audio streamsneed to be transmitted by the workstation. As a result, the necessarybandwidth for each individual workstation 11, 12, 13 is dependent on tohow many radio transmission devices the voice signal of the workstationis transferred simultaneously in the case of a radio transmission, orhow many radio reception devices are listened in on simultaneously bythis workstation. For a radio transmission device, on the other hand,the problem arises that in the event of a simultaneous transmission frommultiple workstations, a multiplicity of voice signals need to betransferred to the radio transmission device, one of which is selectedfor the actual transmission. In the reception direction, radio receptiondevices need to transfer a voice signal to the workstation for eachworkstation that listens in on this radio reception device. Thenecessary bandwidth for each radio device is therefore dependent on howmany workstations 11, 12, 13 simultaneously send a voice signal to aradio transmission device 51, 52, 53 or how many workstations 11, 12, 13simultaneously listen in on the received audio signal of this radioreception device 61, 62, 63.

In modern radio communication systems, the communication links betweenthe workstations 11, 12, 13 and the radio devices 51, 52, 53, 61, 62, 63are set up for local applications not directly but rather in acommunication system, and the workstations 11, 12, 13 or the radiodevices 51, 52, 53, 61, 62, 63 are linked directly to the communicationsystem.

SUMMARY OF THE INVENTION

It is an aim of the invention for any air traffic controller, regardlessof the geographical location of the air traffic control center and hencehis workstation, to be able to access any radio frequency, whatever thegeographical location thereof. In particular, it is an aim of theinvention for multiple air traffic control centers to be combined toform one large virtual control center, or for one control center to beable to undertake the tasks of another without the overall structure ofthe communication system needing to be changed in the process. At thesame time, the required data rates for transfer of the voice signals viathe necessary networks are intended to be optimized.

The invention overcomes the aforementioned problems in a communicationsystem of the type cited at the outset having the characterizingfeatures as claimed.

In achieving this object, the invention can use via wide area networksWAN for the transfer of voice and signaling information, these datanetworks being dimensioned such that the required freedom from blockageand the necessary quality of the voice transfer are ensured in alloperating states of the communication system.

Further, the invention has the aim of providing an improved systemarchitecture that matches the necessary bandwidth and the qualitydemands on transfer to the available network and on the type ofapplication, particularly for tower, remote tower, ACC or virtual ACCapplications.

At the same time, the hardware demands on the workstations 11, 12, 13should be reduced and it should be possible for the components of thecommunication system to be physically concentrated in computer centers8, the dynamic distribution of audio signals being concentrated betweenthe workstations 11, 12, 13 and the radio devices 51, 52, 53, 61, 62, 63in one or more local area networks in accordance with the m:ncommunication matrix. The bandwidth requirement in the interposed widearea networks WAN is intended to be decreased as far as possible.

For all components of the communication system that are able to bedisplaced over a network, the bandwidth requirement should bedeterministic, minimized and static and/or constant. This can beachieved if each component always sends a defined number of voicesignals via the network and the distribution of these voice signalsbetween the components in the local area network takes place in acomputer center 8.

These properties can be used to realize specifically a virtual ACCapplication, wherein workstations 11, 12, 13, computer centers 8,control units and radio devices are operated in a manner geographicallydistributed at different locations and all workstations, regardless oftheir geographical location, can access all radio devices that can bereached via a network. In this case, the necessary data rate in thenetwork is minimized and is deterministic and independent of how manyradio transmission devices or radio reception devices a workstationtalks to or listens in on simultaneously or how many workstations talkto a radio transmission device simultaneously or how many workstationslisten in on a radio reception device.

Usually, the bandwidth of the network connections to the individualradio devices is limited, which means that it is not possible totransfer any amount of audio signals to a radio device and hence havethe radio transmission device make the selection of the voice signal tobe transmitted. Furthermore, radio devices are often only capable oftransferring or receiving one or a few voice signal(s).

In the reception direction, it is likewise not possible for a radioreception device to simultaneously transfer the received voice signal toany amount of workstations that wish to listen in on the same frequency.

The invention overcomes the aforementioned problems and disadvantages ina communication of the type cited at the outset having thecharacterizing features as claimed.

In a communication system for voice communication by means of a numberof workstations, particularly for air traffic controllers, and also anumber of radio transmission devices and radio reception devices,

wherein each of the workstations respectively has at least thefollowing:

at least one voice input unit, particularly a microphone,

at least one voice output unit, particularly a loudspeaker orheadphones,

at least one operator control unit for producing an operator controlsignal that indicates that voice signals are intended to be transferredfrom the respective workstation to one of the radio transmission devicesby means of a voice input unit,

at least one display unit for display of a received signal thatindicates whether voice signals from one of the radio reception devicesare output on the voice output unit, and

at least one selection unit for selection of the radio transmissiondevices and radio reception devices that the workstations use to set upa voice connection on the basis of control signals,

wherein the radio transmission devices are supplied with the voicesignals produced by the voice input units and the operator controlsignals produced by the operator control units, and the radiotransmission device is designed for delivery of the voice signalstransferred by a workstation during simultaneous transmission of anoperator control signal by means of radio, and wherein the radioreception devices are designed for reception of voice signals by meansof radio, the voice signals received by the radio reception devices aresupplied to the individual workstations for delivery by the voice outputunits, and the radio reception devices respectively transmit a receivedsignal to the workstations during the reception of voice signals andforwarding thereof,

there is provision

that a number of control units is provided in the signal path betweenthe workstations and the radio transmission devices and between theworkstations and the radio reception devices, wherein each control unithas a communicative connection to and is associated with at least oneradio transmission device and at least one radio reception device,

wherein the radio transmission devices and radio reception devicesassociated with the same control unit preferably use the same radiofrequency, and wherein particularly each radio transmission device andradio reception device is preferably associated only with a singlecontrol unit,

that multiple workstations are connected to the same control unit,particularly all workstations are connected to all control units, thatthe control units, given the simultaneous presence of a multiplicity ofoperator control signals of multiple distribution units, select thevoice signals of one of the distribution units according to prescribedor prescribable criteria or overlay the voice signals of multipleworkstations according to prescribed criteria and transfer the selectedor overlaid voice signal thus obtained for sending to the radiotransmission device, and that the control units, given the presence of avoice signal transmitted by the radio reception device, transmit areceived signal to the workstations connected to them and transfer thevoice signals to these workstations.

This achieves particularly a simple transfer of data to the radiodevices at a deterministic data rate. Furthermore, there is no longerany need for radio devices to arbitrate the voice radio data supplied toit.

Advantageous linking of multiple radio transmission devices or radioreception devices to a single control unit can be achieved by virtue ofat least one control unit being connected to a plurality of radiotransmission devices, the control unit transmitting the voice signalsarriving at it from a workstation only to one of the radio transmissiondevices or to all radio transmission devices having a connection to itfor transfer, and/or the control unit transmitting the voice signalsthat arrive at it from the radio reception devices to the workstationshaving a voice connection to it.

In order to achieve improved failsafety of radio devices, there may beprovision that the control unit is connected to at least one radiotransmission device and at least one backup radio transmission deviceand that the control unit transfers the voice signals to the radiotransmission device when the latter is functioning and otherwisetransfers the voice signals to the backup radio transmission device,and/or that the control unit is connected to at least one radioreception device and at least one backup radio reception device and thatthe control unit distributes the voice signals arriving at it from theradio reception device to the workstations when the radio receptiondevice connected to said control unit is functioning and otherwisedistributes the voice signals arriving at it from the backup radioreception device to the workstations. This failsafety is the same foreach workstation.

Improved integration of multiple computer centers that use shared radiodevices can be achieved in that the signal path between a control unitand the radio transmission device contains at least one superordinatecontrol unit, the superordinate control unit is connected to a number ofcontrol units, wherein particularly each of these control units isconnected to groups of workstations, the superordinate control unit issupplied with the voice signals and operator control signals deliveredby the control units, wherein the superordinate control unit, givensimultaneous delivery of operator control signals of multiple controlunits connected to it, selects one of the control units according toprescribed or prescribable criteria and forwards the voice signals ofthe selected control unit to the radio transmission device, and thesuperordinate control unit, on reception of voice signals from the radioreception device, forwards these voice signals to the control unitsconnected to the superordinate control unit and transfers a receivedsignal to these control units.

The forwarding of radio data exclusively at the request of theworkstations can be achieved in that the control units or thesuperordinate control units transmit the voice signals arriving at themand the respectively associated received signals merely to a selectionof workstations or control units, wherein preferably the control unitsor the superordinate control units make this selection on the basis ofpreviously made demands by the workstations or the control units.

So as, when there are a multiplicity of different radio transmissiondevices connected to the same control unit, to leave the selection ofthe radio transmission device that is listened in on to the respectiveair traffic controller, there may be provision that the control units orsuperordinate control units directly connected to the radio receptiondevices are respectively connected to a plurality of radio receptiondevices having the same frequency and rate the voice signalssimultaneously arriving at them from the radio reception devices andproduce a rating signal, which indicates particularly

a) a ranking of the arriving voice signals according to signal qualityor

b) the best of the arriving voice signals,

and the control units or superordinate control units directly connectedto the radio reception devices forward the rating signal and also theindividual voice signals of all radio reception devices or the bestvoice signal to the workstations or the control units.

A simple and deterministic way of allowing shared coupling of multiplefrequencies provides that a coupling unit is present that is connectedto two or more control units and/or superordinate control units, whereinthe coupling unit, on arrival of voice signals and of a received signalfrom a control unit or superordinate control unit connected to it,forwards these voice signals and also an operator control signal to theother control units and/or superordinate control units connected to it.

Arbitration can be performed using the coupling unit in that thecoupling unit, on simultaneous arrival of voice signals from two controlunits or superordinate control units connected to it, selects one of thecontrol units or superordinate control units according to prescribed orprescribable criteria and forwards only the voice signals of theselected control unit or superordinate control unit to the remainingcontrol units or superordinate control units connected to the couplingunit.

In order to prevent sensitive information from protected areas frombeing rendered generally accessible, there may be provision that thecoupling unit stores criteria for the forwarding of data of individualcontrol units or superordinate control units to other control units orsuperordinate control units, and that the coupling unit transfers thevoice signals arriving at it to the control units or superordinatecontrol units connected to it according to these criteria.

In order to achieve simple transfer of voice signals between theworkstations and the control units at a deterministic data rate, theremay be provision that the communication system comprises a number ofdistribution units that are respectively associated with a workstation,wherein each workstation has at least one associated distribution unit,that between each of the distribution units and the workstationassociated with this distribution unit there is respectively a logicalor physical data connection having a prescribed bandwidth that can beused to transfer voice signals from each voice input unit and voicesignals to each voice output unit of the workstation and also operatorcontrol signals and received signals, that the distribution unit confersor overlays the voice signals reaching it from radio reception devices,particularly by means of the control units, according to a ruleprescribed on the basis of control signals and transmits the voicesignals ascertained therefrom to the workstation or forwards the voicesignals arriving from a selected radio reception device, particularly bymeans of one of the control units, to the workstation and, if there areactually voice signals present, forwards a received signal to theworkstation, and that the distribution unit transmits, particularly bymeans of one of the control units, voice signals and operator controlsignals transmitted to it by the workstation to radio transmissiondevices previously selected by means of control signals.

A variant that is simple to realize in terms of network engineering andthat avoids the transmission of large volumes of data over longdistances provides that the distribution units are arranged as proxycomputers in a computer center and the control units are also arrangedin this computer center, wherein the control units and the distributionunits are respectively connected to one another via a local areanetwork.

In order to operate separate communication channels using oneworkstation, there may be provision that a workstation has multiplevoice input units and/or multiple voice output units, wherein thecommunication system respectively has, for each voice input unit, aseparate data connection to a distribution unit associated with theworkstation, and wherein the communication system respectively has, foreach voice output unit, a separate data connection to a distributionunit associated with the workstation.

So as, when there are a multiplicity of different radio transmissiondevices connected to the same control unit, to leave the selection ofthe radio transmission device that is listened in on to the respectiveair traffic controller and at the same time to keep down the volume ofdata needing to be transferred over a long distance, there may beprovision that the control unit transmits the rating signal to thedistribution unit, and the distribution unit takes the rating signal asa basis for selecting one of the voice signals transmitted by therespective control unit or takes the rating signal as a basis foroverlaying multiple instances of the voice signals transmitted by therespective control unit on one another and transmits the selected oroverlaid signal to the workstation.

Further, the invention relates to a communication system for voicecommunication by means of a number of workstations, particularly for airtraffic controllers, and also a number of radio transmission devices andradio reception devices,

wherein each of the workstations respectively has at least thefollowing:

at least one voice input unit, particularly a microphone,

at least one voice output unit, particularly a loudspeaker,

at least one operator control unit for producing an operator controlsignal that indicates that voice signals are intended to be transferredfrom the respective workstation to one of the radio transmission devicesby means of a voice input unit,

at least one display unit for reception of a received signal thatindicates whether voice signals from one of the radio reception devicesare output on the voice output unit, and

at least one selection unit for selection of the radio transmissiondevices and radio reception devices that the workstations use to set upa voice connection on the basis of control signals,

wherein the radio transmission devices are supplied with the voicesignals produced by the voice input units and the operator controlsignals produced by the operator control units, and the radiotransmission device is designed for delivery of the voice signalstransferred by a workstation during simultaneous transmission of anoperator control signal by means of radio, and wherein the radioreception devices are designed for reception of voice signals by meansof radio, the voice signals received by the radio reception devices aresupplied to the individual workstations for delivery by the voice outputunits, and the radio reception devices respectively transmit a receivedsignal to the workstations during the reception of voice signals andforwarding thereof. Said communication system has provision that itcomprises a number of distribution units that are respectivelyassociated with a workstation, wherein each workstation has at least oneassociated distribution unit, that between each of the distributionunits and the workstation associated with this distribution unit thereis respectively a logical or physical data connection having aprescribed bandwidth that can be used to transfer voice signals fromeach voice input unit and voice signals to each voice output unit of theworkstation and also operator control signals and received signals, thatthe distribution unit confers or overlays the voice signals reaching itfrom radio reception devices, particularly by means of the controlunits, according to a rule prescribed on the basis of control signalsand transmits the voice signals ascertained therefrom to the workstationor forwards the voice signals arriving from a selected radio receptiondevice, particularly by means of one of the control units, to theworkstation and, if there are actually voice signals present, forwards areceived signal to the workstation, and that the distribution unittransmits, particularly by means of one of the control units, voicesignals and operator control signals transmitted to it by theworkstation to radio transmission devices previously selected by meansof control signals. This achieves particularly a simple transfer ofvoice signals between the workstations and the control units with adeterministic bandwidth.

Furthermore, there may advantageously be provision

that a number of control units is provided in the signal path betweenthe distribution units and the radio transmission devices and betweenthe workstations and the radio reception devices, wherein each controlunit has a connection to and is associated with at least one radiotransmission device and at least one radio reception device,

wherein the radio transmission devices and radio reception devicesassociated with the same control unit preferably use the same radiofrequency, and wherein particularly each radio transmission device andradio reception device is associated only with a single control unit,

that multiple distribution units are connected to the same control unit,particularly all distribution units are connected to all control units,that the control units, given the simultaneous presence of amultiplicity of operator control signals of multiple distribution units,select the voice signals of one of the distribution units according toprescribed or prescribable criteria or overlay the voice signals ofmultiple workstations according to prescribed criteria and transfer theselected or overlaid voice signal thus obtained for sending to the radiotransmission device, and that the control units, given the presence of avoice signal transmitted by the radio reception device, transmit areceived signal to the distribution units connected to said radioreception device and transfer the voice signals to these distributionunits. This achieves particularly a simple transfer of data to the radiodevices at a deterministic data rate. Furthermore, there is no longerany need for radio devices to arbitrate the voice radio data supplied toit.

Advantageous linking of multiple radio transmission devices or radioreception devices to a single control unit can be achieved in that atleast one control unit is connected to a plurality of radio transmissiondevices, the control unit transmits the voice signals arriving at itfrom a distribution unit only to one of the radio transmission devicesor to all radio transmission devices having a connection to it fortransfer, and the control unit transmits the voice signals arriving atit from the radio reception devices to the distribution units having avoice connection to it.

In order to achieve improved failsafety for radio devices, there may beprovision that the control unit is connected to at least one radiotransmission device and at least one backup radio transmission deviceand in that the control unit transfers the voice signals to the radiotransmission device when the latter is functioning and otherwisetransfers the voice signals to the backup radio transmission device,and/or that the control unit is connected to at least one backup radioreception device and in that the control unit distributes the voicesignals arriving at it from the radio reception device to thedistribution units when the radio reception device connected to saidcontrol unit is functioning and otherwise distributes the voice signalsarriving at it from the backup radio reception device to thedistribution units. This failsafety is identical for each workstation.

Improved integration of multiple computer centers that use shared radiodevices can be achieved in that the signal path between a control unitand the radio transmission device contains at least one superordinatecontrol unit, the superordinate control unit is connected to a number ofcontrol units, wherein particularly each of these control units isconnected to groups of respectively different distribution units andworkstations, the superordinate control unit is supplied with the voicesignals and operator control signals delivered by the control units,wherein the superordinate control unit, given simultaneous delivery ofoperator control signals of multiple control units connected to it,selects one of the control units according to prescribed or prescribablecriteria and forwards the voice signals of the selected control unit tothe radio transmission device, and the superordinate control unit, onreception of voice signals form the radio reception device, forwardsthese voice signals to the control units connected to the superordinatecontrol unit and transfers a received signal to these control units.

Forwarding of radio data exclusively at the request of the workstationscan be achieved in that the control units or the superordinate controlunits transmit the voice signals arriving at them and the respectivelyassociated received signal merely to a selection of distribution unitsor control units, wherein preferably the control units or thesuperordinate control units make this selection on the basis ofpreviously made demands by the workstations or the control units.

So as, when there are a multiplicity of different radio transmissiondevices connected to the same control unit, to leave the selection ofthe radio transmission device that is listened in on to the respectiveair traffic controller, there may be provision that the control units orsuperordinate control units directly connected to the radio receptiondevices are respectively connected to a plurality of radio receptiondevices and rate the voice signals arriving at them from the radioreception devices and produce a rating signal, which indicatesparticularly:

a ranking of the arriving voice signals according to signal quality or

the best of the arriving voice signals,

and the control units or superordinate control units directly connectedto the radio reception devices forward the rating signal and also theindividual voice signals of all radio reception devices to thedistribution unit or the control units.

So as, when there are a multiplicity of different radio transmissiondevices connected to the same control unit, to leave the selection ofthe radio transmission device that is listened in on to the respectiveair traffic controller and at the same time to keep down the volume ofdata to be transferred over a long distance, there may be provision thatthe control unit transmits the rating signal to the distribution unit,and the distribution unit takes the rating signal as a basis forselecting one of the voice signals transmitted by the respective controlunit or takes the rating signal as a basis for overlaying multipleinstances of the voice signals transmitted by the respective controlunit on one another and transmits the selected or overlaid signal to therespective workstation connected to the distribution unit.

A simple and deterministic way of allowing shared coupling of multiplefrequencies provides that a coupling unit is present that is connectedto two or more control units and/or superordinate control units, whereinthe coupling unit, on arrival of voice signals and of a received signalfrom a control unit or superordinate control unit connected to it,forwards these voice signals and also an operator control signal to theother control units and/or superordinate control units connected to it.

Arbitration can be performed using the coupling unit in that thecoupling unit, on simultaneous reception of voice signals from twocontrol units or superordinate control units connected to it, selectsone of the control units or superordinate control units according toprescribed or prescribable criteria and forwards only the voice signalsof the selected control unit or superordinate control unit to theremaining control units or superordinate control units connected to thecoupling unit.

To prevent sensitive information from protected areas from beingrendered generally accessible, there may be provision that the couplingunit stores criteria for the forwarding of data of individual controlunits or superordinate control units to other control units orsuperordinate control units, and the coupling unit transfers the voicesignals arriving at it to the control units or superordinate controlunits connected to it according to these criteria.

A variant that is simple to realize in terms of network engineering andthat avoids the transmission of large volumes of data over a longdistance provides that the distribution units are arranged as proxycomputers in the computer center and the control units are also arrangedin this computer center, wherein the control units and the distributionunits are respectively connected to one another via a local areanetwork.

In order to operate separate communication channels using oneworkstation, there may be provision that a workstation has multiplevoice input units and/or multiple voice output units, wherein thecommunication system respectively has, for each voice input unit, aseparate data connection to a distribution unit associated with theworkstation, and wherein the communication system respectively has, foreach voice output unit, a separate data connection to a distributionunit associated with the workstation.

In a method for transferring voice data from a number of workstations,particularly for air traffic controllers, respectively comprising:

at least one voice input unit, particularly a microphone,

at least one voice output unit, particularly a loudspeaker orheadphones,

at least one operator control unit for producing an operator controlsignal that indicates that voice signals are intended to be transferredfrom the respective workstation to one of the radio transmission devicesby means of a voice input unit,

at least one display unit for display of a received signal thatindicates whether voice signals from one of the radio reception devicesare output on the voice output unit, and

at least one selection unit for selection of the radio transmissiondevices and radio reception devices that the workstations use to set upa voice connection on the basis of control signals,

by means of a number of radio transmission devices and radio receptiondevices,

wherein the voice signals produced by the voice input units and theoperator control signals produced by the operator control units aretransferred to the radio transmission devices, and the voice signalsdelivered by a workstation are forwarded to the radio transmissiondevice and, during simultaneous transmission of an operator controlsignal by the workstation, are sent by said radio transmission device bymeans of radio,

wherein the radio reception devices receive voice signals by means ofradio and these voice signals are forwarded to the workstations and areoutput using the voice output units, wherein during the reception ofvoice signals and during the forwarding of voice signals to theworkstations a received signal is respectively transmitted to therespective workstation and displayed by the display unit,

there is provision that voice data are transmitted from the workstationsto the radio transmission devices and radio reception devices viacontrol devices, that the control units, given the simultaneous presenceof a multiplicity of operator control signals of multiple workstations,select the voice signals of one of the workstations according toprescribed or prescribable criteria or overlay the voice signals ofmultiple workstations according to prescribed criteria and transfer theselected voice signal, or voice signal overlaid on the radiotransmission device, thus obtained for sending, and that the controlunits, given the presence of a voice signal transmitted by the radioreception device, transmit to the workstations connected to them areceived signal and transfer the voice signals to these workstations.This achieves particularly a simple transfer of data to the radiodevices at a deterministic data rate. Furthermore, there is no longerany need for radio devices to arbitrate the voice radio data supplied toit.

Furthermore, the invention relates to a method for transferring voicedata from a number of workstations, particularly for air trafficcontrollers, respectively comprising:

at least one voice input unit, particularly a microphone,

at least one voice output unit, particularly a loudspeaker orheadphones,

at least one operator control unit for producing an operator controlsignal that indicates that voice signals are intended to be transferredfrom the respective workstation to one of the radio transmission devicesby means of the voice input unit,

at least one display unit for display of a received signal thatindicates whether voice signals from one of the radio reception devicesare output on the voice output unit, and

-   -   at least one selection unit for selection of the radio        transmission devices and radio reception devices that the        workstations use to set up a voice connection on the basis of        control signals,

by means of a number of radio transmission devices and radio receptiondevices,

wherein the voice signals produced by the voice input units and theoperator control signals produced by the operator control units aretransferred to the radio transmission devices, and the voice signalsdelivered by a workstation are forwarded to the radio transmissiondevice and, during simultaneous transmission of an operator controlsignal by the workstation, are sent by said radio transmission device bymeans of radio,

wherein the radio reception devices receive voice signals by means ofradio and these voice signals are forwarded to the workstations and areoutput using the voice output units, wherein during the reception ofvoice signals and during the forwarding of the voice signals to theworkstations a received signal is respectively transmitted to therespective workstation and displayed by the display unit. Said methodhas provision that a workstation service is respectively carried out forthe workstations on computers arranged remotely from the workstations,particularly on a distribution unit, wherein each workstation isassigned at least one workstation service, and that a logical orphysical data connection having a prescribed bandwidth is respectivelycreated between the workstation service and the workstation associatedwith this workstation service, which data connection is used to transfervoice signals from the voice input unit and voice signals to the voiceoutput unit of the workstation and also operator control signals andreceived signals, that the workstation service confers or overlays thevoice signals reaching it from radio reception devices, particularly bymeans of the control units, according to a rule prescribed on the basisof control signals and transmits the voice signals ascertained therefromto the workstation or forwards the voice signals arriving from aselected radio reception device, particularly by means of one of thecontrol units, to the workstation and, if there are actually voicesignals present, forwards a received signal to the workstation, and theworkstation service transmits the voice signals and operator controlsignals that have been transmitted to it by the workstation to radiotransmission devices, particularly by means of one of the control unitsthat have previously been selected by means of control signals. Thisachieves particularly a simple transfer of voice signals between theworkstations and the control units with a deterministic bandwidth.

A further aspect of the invention provides that the selection of thevoice signal to be sent or the distribution of a received voice signalis made at a location that, from the point of view of the network, islinked with greater bandwidth to the workstations via a network, so asto be able to simultaneously receive the voice signals from multipleworkstations or simultaneously send voice signals to multipleworkstations and then also be able to make the decision about the signalto be sent. This means that only one voice signal needs to betransferred to the radio transmission device or only one voice signalneeds to be transferred from the radio reception device. This function,which realizes the linking of radio transmission devices and radioreception devices, is referred to as a whole as frequency service and isrealized by a control unit.

The introduction of control devices on which frequency services areimplemented links the radio devices directly to the frequency service orthe control unit, and there is only the transfer of the voice signalselected by the frequency service to one or more radio transmissiondevices, or the control unit undertakes distribution of the voice signalreceived by one or more radio reception devices to the workstations.This means that there is also no longer any need for the voice signalsto be transferred from and to the radio devices in compressed fashion soas thereby to save bandwidth or to minimize the required bandwidth or touse network mechanisms such as multicasting for the transfer of audiosignals between the workstations and the radio devices, the use of whichnetwork mechanisms is problematic via wide area networks WAN.

At the same time, it is also possible for multiple radio devices thatare located at different radio sites and are operated at the samephysical frequency to be combined in a frequency service by a sharedcontrol unit, selection of the signal to be transmitted and selection ofthe radio site being undertaken by the frequency service. The frequencyservice or the control unit can also undertake further functions andmake the functions realized thereby available to all users. Thesecomprise, by way of example:

-   -   rating of the receiver signals on simultaneous reception by        multiple radio reception devices associated with the frequency        service, on the basis of different quality parameters for the        received signal, and possibly an additional optional signal        selection,    -   dynamic selection of one or more radio transmission devices        having one frequency during CLIMAX operation for a radio        transmission. This function may also be dependent on a preceding        reception, which is referred to as “transmitter follows        receiver”,    -   changeover to a substitute radio device, main/standby        changeovers, in the event of the active radio device being        faulty,    -   dynamic delay time compensation for the propagation time of an        audio signal between workstation and multiple radio transmission        devices having one frequency during CLIMAX operation, etc.

If a communication system contains m workstations and n frequencyservices, each frequency service in turn being able to combine multipleradio devices, then it is possible for each workstation to transmit onor listen in on any number of frequency services simultaneously. Thisresults in an m:n communication matrix between the workstations and thefrequency services or control unit. Which frequency services or controlunit a workstation is actually permitted to access is stipulated by theconfiguration of the workstations, which configuration can be changedaccording to the operational requirements. The actual use of a frequencyservice or control unit is dependent on the keying by the user.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 shows a diagram of a communication system according to the priorart;

FIGS. 2-6 illustrate possible realizations of communication systemsaccording to the invention.

FIG. 2 schematically shows the design of a first embodiment of acommunication system according to the invention, wherein control unitshaving frequency services are provided. FIG. 3 schematically shows thedesign of a second communication system according to the invention,wherein distribution units are provided that act as workstation proxycomputers. FIG. 4 shows a third embodiment of the invention with acombination of the features depicted in FIGS. 2 and 3. FIG. 5 shows afourth embodiment of the invention, wherein multiple mutuallyindependent computer centers and superordinate control units areprovided. FIG. 6 shows an alternative to the third embodiment of theinvention, wherein two control units are coupled to one another.

DESCRIPTION OF THE INVENTION

Between the frequency service and each individual radio transmissiondevice or radio reception device, there is a logical 1:1 communicationlink, as a result of which the necessary data rate between the frequencyservice and the radio devices remains limited and deterministic,regardless of how many workstations 11, 12, 13 actually use a frequencyor a distribution unit 31, 32, 33. Hence, the necessary data ratebetween the radio devices and the frequency service is minimized, as aresult of which audio compression of the voice signals on thistransmission link is not absolutely necessary.

The frequency service implemented in the control unit 31, 32, 33 is usedfor the setup and monitoring of the audio connections to the radiotransmission device and radio reception device allocated to thefrequency service, each frequency service managing a prescribed radiofrequency.

The first embodiment of the invention, depicted in FIG. 2, comprises anumber of workstations 11, 12, 13 that are connected to control units31, 32, 33 via a wide area network. Each of the workstationsrespectively has at least one voice input unit 111, 121, 131, this beinga microphone in the present case. Furthermore, each workstationrespectively has at least a voice output unit 112, 122, 132, which arein the form of loudspeakers or headphones in the present case.Furthermore, the individual workstations 11, 12, 13 have an operatorcontrol unit 113, 123, 133, these respectively being able to be used toproduce and transmit an operator control signal PTT. This operatorcontrol signal indicates that the respective workstation 11, 12, 13 isintended to use the voice input unit 111, 121, 131 to transfer voicesignals to one of the radio transmission device 51, 52, 53. Furthermore,each of the workstations has a display unit 114, 124, 134 for displayinga received signal SQU. Furthermore, the workstations have a selectionunit, not depicted, for selecting that radio transmission device 51, 52,53 and radio reception device 61, 62, 63 to which the respectiveworkstation wishes to send voice signals or from which the respectiveworkstation 11, 12, 13 wishes to receive voice signals. The controlunits 31, 32, 33, which are connected to the workstations 11, 12, 13 viathe wide area network WAN, are for their part connected to a radiotransmission device 51, 52, 52 a, 53, 53 a and to a radio receptiondevice 61, 62, 62 a, 63, 63 a. This means that the control units 31, 32,33 are in the signal path between the workstations 11, 12, 13 and theradio transmission device 51, 52, 53 or the radio reception device 61,62, 63.

As already known in the prior art, the radio transmission devices 51,52, 53 are supplied with the voice signals produced by the voice inputunits 111, 121, 131 and the operator control signals produced by theoperator control units 113, 123, 133 indirectly via the control units31, 32, 33. The radio transmission device 51, 52, 53 is designed fordelivery of the voice signals transferred by a workstation 11, 12, 13during simultaneous transmission of an operator control signal PTT bymeans of radio. Similarly, the radio reception devices 61, 62, 63respectively transmit a received signal SQU during the reception ofvoice signals and during forwarding thereof to the workstations 11, 12,13. The radio reception devices 61, 62, 63 are designed for reception ofvoice signals by means of radio, the voice signals received by the radioreception devices 61, 62, 63 being supplied by individual workstations11, 12, 13 for delivery to the voice output units 112, 122, 132.

As is evident from the present first exemplary embodiment, each controlunit 31, 32, 33 has a communication connection to at least one radiotransmission device 51, 52, 53 and to at least one radio receptiondevice 61, 62, 63. In this advantageous embodiment of the invention, theradio devices 51, 61 associated with the control unit 31 use the samefrequency. Similarly, the radio devices 52, 52 a, 62, 62 a associatedwith the second control unit 52 use a shared frequency and the radiodevices 53, 53 a, 63, 63 a associated with the control unit 33 likewiseuse a shared frequency. The effect achieved by this measure is that thefrequency services executed in the control units 31, 32, 33 arerespectively used to manage a radio frequency in a particular area. Thecontrol units 31, 32, 33 allow simultaneous connection to one or more ofthe workstations 11, 12, 13 via the wide area network. In particular,all of the workstations 11, 12, 13 may be connected to all control units31, 32, 33 via the wide area network.

In the first embodiment of the invention depicted in FIG. 2, the controlunits 31, 32, 33 undertake the task of arbitrating the outgoing voicesignals to be transmitted by the workstations and distributing the voicesignals arriving from the radio reception devices 61, 62, 62 a, 63, 63 ato the workstations. In the event of the simultaneous presence of anumber of operator control signals PTT from multiple workstations 11,12, 13, the control units 31, 32, 33 select the voice signals of one ofthe workstations 11, 12, 13 according to prescribed or prescribablecriteria. Alternatively, there is the option for the voice signals ofthe individual workstations 11, 12, 13 to be overlaid according toprescribed criteria. The voice signal of this kind, selected or obtainedby overlaying, is transmitted to the radio transmission device 51, 52,53 and beamed by this radio transmission device. To forward the voicesignals arriving at the respective radio reception installation 61, 62,63, the control units transmit the voice signals transmitted to them tothe workstations 11, 12, 13 connected to them a received signal SQU andalso the voice signals to be received.

In the practical realization, a frequency service and also theadditional services described in the later part of the text consist ofat least one software component in which the control and communicationfunctions of the frequency service are realized and at least onesoftware component in which the processing and distribution of the audiosignals together with the signaling information PTT and SQU arerealized. These software components can be executed together in a PCserver or in a specific hardware component. However, it is equallypossible for the software components to be executed on different PCservers, in different virtual machines or on specific hardwarecomponents, or for the software component of the audio transfer anddistribution to be operated repeatedly, for example, in order to be ableto realize a redundant transfer of the audio signals.

The transfer of voice and signaling information is increasingly realizedusing data distribution networks specific to air traffic control, as aresult of which the air traffic controller workstations can bephysically separated from the frequency services connected to the radiodevices over longer distances. Transfer of the voice and signalinginformation between the workstations 11, 12, 13 and the control units31, 32, 33 is effected via wide area networks WAN, and the individualradio devices are frequently connected to the control unit via lineswith low bandwidth.

The first embodiment of the invention allows voice signals to betransferred in a manner free from blockage. If, in a first embodiment ofthe invention, a workstation 11, 12, 13 wants to send voice signals tomultiple frequency services or control units 31, 32, 33, the same voicesignal is transferred to each frequency service that has been selectedby this workstation 11, 12, 13. Overall, this means that the same voicesignal is transferred repeatedly in the data network. If, on the otherhand, a frequency service is listened in on by multiple workstations 11,12, 13, then said frequency service the same voice signal is transmittedto each workstation 11, 12, 13. This means that this voice signal islikewise transferred repeatedly in the network.

FIG. 3 depicts a second embodiment of the invention in more detail. Thisembodiment shows a communication system for voice communication by meansof a number of workstations 11, 12, 13 for air traffic controllers. Thecommunication system comprises a number of radio transmission devices51, 52, 53 and radio reception devices 61, 62, 63. As in the case of thefirst exemplary embodiment of the invention too, each of theworkstations 11, 12, 13 respectively has at least the following:

-   -   at least one voice input unit 111, 121, 131, particularly a        microphone,    -   at least one voice output unit 112, 122, 132, particularly a        loudspeaker,    -   at least one operator control unit 113, 123, 133 for producing        an operator control signal PTT that indicates that voice signals        are intended to be transferred from the respective workstation        11, 12, 13 to one of the radio transmission devices 51, 52, 53        by means of the voice input unit 111, 121, 131,    -   at least one display unit 114, 124, 134 for display of a        received signal SQU that indicates whether voice signals from        one of the radio reception devices 61, 62, 63 are output on the        voice output unit 112, 122, 132, and    -   at least one selection unit for selection of the radio        transmission devices 51, 52, 53 and radio reception devices 61,        62, 63 that the workstations use to set up a voice connection on        the basis of control signals.

The workstations 11, 12, 13 transmit the voice signals produced by thevoice input units 111, 121, 131 and the operator control signals PTTproduced by the operator control units 113, 123, 133 to the distributionunits 21, 22, 23, which forward the voice signals to the radiotransmission devices 51, 52, 53. The latter deliver the voice signalstransferred by a workstation 11, 12, 13 during simultaneous transmissionof an operator control signal PTT. The radio reception devices 61, 62,63 receive voice signals by means of radio. The voice signals receivedby the radio reception devices 61, 62, 63 are supplied to the individualdistribution units 21, 22, 23, which forward the voice signals to theworkstations 11, 12, 13. The voice signals are delivered to therespective voice output units 112, 122, 132 by the workstations 11, 12,13. The radio reception devices 61, 62, 63 respectively transmit areceived signal SQU to the workstations 11, 12, 13 via the distributionunits 21, 22, 23 during the reception of voice signals and forwardingthereof.

The communication system additionally has a number of distribution units21, 22, 23 that are respectively associated with a workstation 11, 12,13, each workstation 11, 12, 13 having at least one, in the present caseprecisely one, associated distribution unit 21, 22, 23. Between each ofthe distribution units 21, 22, 23 and the workstation 11, 12, 13associated with this distribution unit 21, 22, 23 there is respectivelya logical or physical data connection having a prescribed bandwidth,which can be used to transfer voice signals from each voice input unit111, 121, 131 and voice signals to each voice output unit 112, 122, 132of the workstation 11, 12, 13 and also operator control signals PTT andreceived signals SQU.

The distribution unit 21, 22, 23 confers or overlays the voice signalsreaching it from radio reception devices 61, 62, 63 according to a ruleprescribed on the basis of control signals. The voice signalsascertained therefrom are transmitted by said distribution unit to theworkstation 11, 12, 13. If there are actually voice signals present, thedistribution unit forwards a received signal SQU to the workstation 11,12, 13. The respective distribution unit 21, 22, 23 transmits its voicesignals transmitted by the workstation 11, 12, 13 to radio transmissiondevices 51, 52, 53 previously selected by means of control signals.

In the second embodiment of the invention, the required bandwidth ordata rate for the transfer of the voice signals from the workstations tothe distribution units is constant and independent of the number offrequencies or radio devices talked on and listened in on.

The third embodiment of the invention, described below and depicted inFIG. 4, is intended to avoid the disadvantages of inefficientutilization of the bandwidth available in the network and thedisadvantage of a nondeterministic bandwidth requirement for theindividual components. The third embodiment of the invention is depictedon the basis of the first embodiment of the invention and essentiallyhas the features of the first two embodiments of the invention.

-   -   Identical voice signals are now intended to be transferred via        the network only once, resulting in more efficient utilization        of the available bandwidth and avoiding unnecessary        overdimensioning of the network.    -   From the point of view of the individual components workstations        11, 12, 13 and control unit 31, 32, 33, the bandwidth        requirement therefor when accessing the network is limited at        the top and, for each workstation 11, 12, 13, independent of the        number of control units 31, 32, 33 that a workstation 11, 12, 13        simultaneously uses, listens in on and/or talks on, or, for each        control unit 31, 32, 33, independent of the number of        workstations that simultaneously listen in on it.    -   In addition to the communication structure depicted in FIG. 2,        the system architecture is improved by also introducing, for        each workstation 11, 12, 13, an additional workstation service        that is implemented in a distribution unit 21, 22, 23.    -   This results in a structure in which the workstations 11, 12, 13        can be arranged remotely from the control units 31, 32, 33 over        any distances via a wide area network WAN.

The workstation service executed on the distribution unit 21, 22, 23realizes all radio functions of a workstation 11, 12, 13 and allowsdisplaced linking of the operator control units and the audioinput/output units. It firstly transfers the voice signals of aworkstation 11, 12, 13 to all control units 31, 32, 33 or frequencyservices used and, secondly, it receives all voice signals form thecontrol units 31, 32, 33 or frequency services and forwards them to theworkstation 11, 12, 13, these voice signals being conferred inaccordance with their allocation to audio output units of theworkstation 11, 12, 13, such as e.g. headphones, loudspeakers, . . . .

In this case, it is possible for the possible m:n communication linksbetween the workstation services in the distribution unit 21, 22, 23 andthe frequency services in the control units 31, 32, 33 to be realized inthe local area network 81 of a computer center 8. In comparison with awide area network, FIG. 2, the bandwidth requirement in a local areanetwork 81 plays a subordinate part in the costs and in the dimensioningof the network components. Similarly, it is possible for differentdistribution mechanisms, e.g. multicast groups, to be realized moreeasily in a local area network 81.

Each workstation 11, 12, 13 is therefore respectively linked via a widearea network to a workstation service or a distribution unit 21, 22, 23,as a result of which the bandwidth necessary therefor is low anddeterministic, no signals need to be transferred repeatedly and noadditional voice signals need to be transferred during operation even inthe event of a change in the frequency services used by the workstation11, 12, 13. Between the workstation and the workstation service or thedistribution unit 21, 22, 23, there therefore exists a strict logical1:1 communication link, as a result of which the data rate necessary perworkstation 11, 12, 13 in the wide area network is minimized,deterministic and also limited.

The frequency service implemented in the control unit 31, 32, 33 is usedfor the setup and monitoring of the audio connections to the radiotransmission device and radio reception device allocated to thefrequency service operation with overlapping chains or CLIMAX operation,each frequency service managing a prescribed radio frequency.

Between the frequency service and the radio transmitters and radioreceivers, there is a logical 1:1 communication link, as a result ofwhich the necessary bandwidth between the frequency service and theradio devices remains limited and deterministic regardless of how manyworkstations 11, 12, 13 actually use a frequency or a distribution unit31, 32, 33. Hence, the necessary bandwidth between the radio devices andthe frequency service is minimized, as a result of which audiocompression of the voice signals for bandwidth minimization on thistransmission link is not absolutely necessary.

So that a frequency service or a control unit 31, 32, 33 has multipleassociated radio reception devices 61, 62, 63 and any user can select aspecific location or, in the event of operation with best signalselection, the selection of the frequency service can be individuallyoverruled by any user, the voice signals of all radio reception devices62 a, 62 of a control unit 31, 32, 33 are transferred to thedistribution unit 21, 22, 23, so as to be able to perform the applicableselection there. The quality of the received signals is rated in thecontrol unit 31, 32, 33, this information is transferred to therespective distribution units 21, 22, 23, and the actual selection ofthe voice signal to be sent to the workstation is first made by theworkstation service in the distribution unit. This means that it ispossible to realize standard rating and ranking of the received voicesignals across the system and still to provide every operator with theopportunity to be able to make an individual selection from the voicesignals of each frequency service.

In a fourth embodiment of the invention, multiple radio communicationsystems can be interconnected to form virtual centers. FIG. 5 shows anexample of the communication structures of such a communication system,in the individual computer centers 8 a, 8 b being connected to the radiodevices via superordinate control units 41, 42, 43.

The individual control units 31 a-33 a, 31 b-33 b arranged in thecomputer centers 8 a, 8 b have a reduced scope of functions incomparison with the frequency services of the previous embodiment of theinvention. They arbitrate the voice signals from the workstationservices of a computer center 8a, 8 b for a superordinate control unit41, 42, 43 in the transmission direction and, secondly, distributes thevoice signals of the control unit to the workstation services of thedistribution unit 21, 22, 23 of a computer center 8 a, 8 b in thereception direction, e.g. for all users who want to listen in on thisfrequency.

For each frequency, there is precisely one control unit 31 a-33 a, 31b-33 b available in a computer center. A superordinate control unit 41,42, 43, which can be operated at a different geographical location thana computer center, controls the control units 31 a-33 a, 31 b-33 b ofdifferent computer centers 8 a, 8 b, as a result of which no voicesignals are transferred repeatedly on the connection between a controlunit 31 a-33 a, 31 b-33 b and a superordinate control unit and hence therequired bandwidth via the WAN is static and deterministic.Additionally, an active connection between a control unit 31 a-33 a, 31b-33 b and a superordinate control unit 41, 42, 43 in a computer center8 a, 8 b is necessary only when at least one workstation 11, 12, 13 inthis computer center 8 a, 8 b has keyed in this frequency.

To realize a virtual control center, it is not absolutely necessary forthe workstations 11-16 to be always connected to the same computercenter 8 a, 8 b. For example, it is possible to realize structures thatallow the following operating conditions:

In the event of failure of a computer center 8 a, 8 b, workstations11-16 and superordinate control units 41, 42, 43 are connected to abackup computer center in order to maintain operation.

At small airports, it may make sense for operation during the nighthours to be intended to be undertaken by other workstations in a largerworkstation control center, for example.

At very small airports, it may make sense for the computer centers notto be designed to have the distribution units, and to have theworkstations 11-16 communicate directly with the superordinate controlunits 41, 42, 43, for example.

In the first, third and fourth embodiments of the invention, there isthe option of realizing coupling between two or more frequencies. By wayof example, the third embodiment of the invention in FIG. 6 is used todepict an extension that involves frequencies being coupled to oneanother. For this purpose, additional coupling services 7 are realizedin the computer center 8. When an operator wishes to couple two or morefrequencies respectively managed by control units 31, 32, 33 to oneanother, this coupling is assigned to a coupling service 7, whichforwards the signals that are received from a frequency service or acontrol unit 31, 32, 33 to the other selected control units—the termcoupling group is also used—in order to transmit the signal on allselected frequencies. The advantage of this solution is that, incontrast to coupling directly at the workstation, the delay times in thecoupling loop are reduced, since the voice signals do not have to betransferred twice via the wide area network.

A further advantage of this solution is the central management of acoupling group, as a result of which it is possible for couplings of thesame frequencies by multiple users to be regulated once centrally in thecoupling service 7 rather than in a manner distributed in theworkstations 11, 12, 13 and control units that are involved. This allowsruntime effects and reciprocal blockage to be avoided.

1. A method for transferring voice data from a plurality of workstationsby way of a plurality of radio transmission devices and radio receptiondevices, workstations respectively comprising: at least one voice inputunit, at least one voice output unit, at least one operator control unitfor producing an operator control signal that indicates that voicesignals are intended to be transmitted from the respective workstationto one of the radio transmission device by way of the voice input unit;at least one display unit for display of a received signal thatindicates whether voice signals from one of the radio reception devicesare output on the voice output unit; and at least one selection unit forselection of the radio transmission devices and the radio receptiondevices that the workstations use to set up a voice connection on thebasis of control signals; the method comprising: transferring the voicesignals produced by the voice input units and the operator controlsignals produced by the operator control units to the radio transmissiondevices, and forwarding the voice signals delivered by a workstation tothe radio transmission device and, sending, during simultaneoustransmission of an operator control signal by the workstation, by theradio transmission device by way of radio; receiving by the radioreception devices voice signals by radio and forwarding the voicesignals to the workstations and outputting the voice signals using thevoice output units, wherein during the reception of voice signals andduring the forwarding of voice signals to the workstations a receivedsignal is respectively transmitted to the respective workstation anddisplayed by the display unit; carrying out a workstation servicerespectively for the workstations on computers arranged remotely fromthe workstations, wherein each workstation is assigned at least oneworkstation service; establishing a logical or physical data connectionhaving a prescribed bandwidth respectively between the workstationservice and the workstation associated with the workstation service, andusing the data connection to transfer voice signals from the voice inputunit and voice signals to the voice output unit of the workstation andalso operator control signals and received signals; conferring oroverlaying the voice signals reaching the workstation service from radioreception devices according to a rule prescribed on the basis of controlsignals and transmitting the voice signals ascertained therefrom to theworkstation or forwarding the voice signals arriving from a selectedradio reception device to the workstation and, if there are voicesignals actually present, forwarding a received signal to theworkstation; and transmitting with the workstation service the voicesignals and operator control signals that have been transmitted to theworkstation to radio transmission devices that have previously beenselected by way of the control signals.
 2. The method according to claim1, wherein: a plurality of control units are arranged in a signal pathbetween the distribution units and the radio transmission devices andbetween the workstations and the radio reception devices, wherein eachcontrol unit is assigned at least one radio transmission device and atleast one radio reception device; multiple distribution units areconnected to the same control unit; the control units, given asimultaneous presence of a multiplicity of operator control signals atmultiple distribution units, select the voice signals of one of thedistribution units according to prescribed or prescribable criteria andtransfer the voice signals to the radio transmission device for sending;and the control units, given a presence of a voice signal transmitted bythe radio reception device, transmit a received signal to thedistribution units connected to the radio reception device and transferthe voice signals to these distribution units.
 3. The method accordingto claim 2, wherein: a plurality of control units are arranged in asignal path between the workstation services and the radio transmissiondevices and between the workstation services and the radio receptiondevices, wherein each control unit has a communicative connection set upfor it to at least one radio transmission device and at least one radioreception device; wherein the radio transmission devices and radioreception devices associated with the same control unit use the sameradio frequency, and wherein each radio transmission device and radioreception device is assigned only to a single control unit; and multipleworkstations are connected to the same control unit.
 4. The methodaccording to claim 2, wherein: at least one control unit is connected toa plurality of radio transmission devices; the control unit transmitsthe voice signals arriving from a distribution unit only to one of theradio transmission devices or to all radio transmission devices having aconnection to the control unit for transfer; and the control unittransmits the voice signals arriving at it from the radio receptiondevices to the distribution units having a voice connection to thecontrol unitt.
 5. The method according to claim 2, wherein: the controlunit is connected to at least one radio transmission device and at leastone backup radio transmission device and the control unit transfers thevoice signals to the radio transmission device when the latter isfunctioning and otherwise transfers the voice signals to the backupradio transmission device; and/or the control unit is connected to atleast one backup radio reception device and the control unit distributesthe voice signals from the radio reception device to the distributionunits when the radio reception device connected to the control unit isfunctioning and otherwise distributes the voice signals from the backupradio reception device to the distribution units.
 6. The methodaccording to claim 2, wherein: the signal path between a control unitand the radio transmission device contains at least one superordinatecontrol unit connected to a plurality control units (31 a-33 a, 31 b-33b), wherein particularly each of these control units (31 a-33 a, 31 b-33b) is connected to groups of workstations; the voice signals andoperator control signals delivered by the control units (31 a-33 a, 31b-33 b) are transferred to the superordinate control unit, wherein thesuperordinate control unit, given simultaneous delivery of operatorcontrol signals of multiple control units (31 a-33 a, 31 b-33 b)connected to it, selects one of the control units (31 a-33 a, 31 b-33 b)according to prescribed or prescribable criteria and forwards the voicesignals of the selected control unit to the radio transmission device;and the superordinate control unit, on reception of voice signals fromthe radio reception device, forwards these voice signals to the controlunits (31 a-33 a, 31 b-33 b) connected to the superordinate control unitand transfers a received signal to these control units (31 a-33 a, 31b-33 b).
 7. The method according to claim 6, which comprises using thecontrol units or the superordinate control units to transmit the voicesignals arriving at them and the respectively associated received signalmerely to a selection of workstation services, distribution units orcontrol units.
 8. The method according to claim 7, which comprisesdefining the selection by the control units or the superordinate controlunits on a basis of previously made demands by the workstations or thecontrol units.
 9. The method according to claim 6, wherein the controlunits or superordinate control units directly connected to the radioreception devices are respectively connected to a plurality of radioreception devices and rate the voice signals arriving at them from theradio reception devices and produce a rating signals, the rating signalsindicating: a) a ranking of the arriving voice signals according tosignal quality or b) the best of the arriving voice signals; the controlunits or superordinate control units directly connected to the radioreception devices forwarding the rating signal and also the individualvoice signals of all radio reception devices to the distribution unit orthe control units.
 10. The method according to claim 9, which comprisestransmitting with the control unit the rating signal to the distributionunit, and the distribution unit taking the rating signal as a basis forselecting one of the voice signals transmitted by the respective controlunit or taking the rating signal as a basis for overlaying multipleinstances of the voice signals transmitted by the respective controlunit on one another and transmitting the selected or overlaid signal tothe respective workstation.
 11. The method according to claim 2, whichcomprises: prescribing a coupling group that comprises two or morecontrol units and/or superordinate control units; and on arrival ofvoice signals and of a received signal from a control unit orsuperordinate control unit of the coupling group, transmitting thesevoice signals and an operator control signal to the other control unitsand/or superordinate control units of the coupling group.
 12. The methodaccording to claim 11, which comprises, on simultaneous arrival of voicesignals from two control units or superordinate control units of thecoupling group, selecting one of the control units or superordinatecontrol units according to prescribed or prescribable criteria andforwarding only the voice signals of the selected control unit orsuperordinate control unit to the remaining control units orsuperordinate control units of the coupling group.
 13. The methodaccording to claim 11, which comprises: prescribing criteria for theforwarding of data of individual control units or superordinate controlunits to other control units or superordinate control units of thecoupling group; and on arrival of voice signals from a control unit orsuperordinate control unit of the said coupling group, transferringvoice data to the control units or superordinate control units of thecoupling group according to the prescribed criteria.
 14. The methodaccording to claim 1, which comprises executing the workstation serviceson proxy computers and using control units to communicate with oneanother.
 15. The method according to claim 14, which comprises executingthe workstation services on distribution units in a computer center andusing control units that are likewise arranged in the computer center toexchange voice signals via a local area network.
 16. The methodaccording to claim 1, wherein a workstation has multiple voice inputunits and/or multiple voice output units and the method comprises:transferring with each voice input unit voice signals to the respectiveworkstation service via a separate data connection; and transferringvoice signals to each voice output unit by the respective workstationservice via a separate data connection.
 17. A communication system forvoice communication, the system comprising: a plurality of radiotransmission devices and radio reception devices; a plurality ofworkstations, each of said workstations including: at least one voiceinput unit; at least one voice output unit; at least one operatorcontrol unit for producing an operator control signal that indicatesthat voice signals are intended to be transferred from the respectivesaid workstation to one of said radio transmission devices by way of avoice input unit; at least one display unit for displaying a receivedsignal that indicates whether voice signals from one of the radioreception devices are output on the voice output unit; at least oneselection unit for selection of said radio transmission devices andradio reception devices that are used by said workstations to set up avoice connection on the basis of control signals; wherein said radiotransmission devices are supplied with the voice signals produced bysaid voice input units and the operator control signals produced by saidoperator control units, and said radio transmission devices areconfigured for delivery of the voice signals transferred by a respectivesaid workstation during a simultaneous radio transmission of an operatorcontrol signal; wherein said radio reception devices are configured forreceiving voice signals by way of radio, the voice signals received bysaid radio reception devices are supplied to the individual saidworkstations for delivery by said voice output units, and said radioreception devices respectively transmit a received signal to saidworkstations during a reception and forwarding of the voice signals; aplurality of control units disposed in a signal path between saidworkstations and said radio transmission devices and between saidworkstations and said radio reception devices, each said control unithaving a communicative connection to, and being associated with, atleast one said radio transmission device and at least one said radioreception device; wherein multiple said workstations are connected toone and the same said control unit; said control units, given asimultaneous presence of a multiplicity of operator control signals ofmultiple distribution units, selecting the voice signals of one of saiddistribution units according to prescribed or prescribable criteria oroverlay the voice signals of multiple workstations according toprescribed criteria and transferring the selected or overlaid voicesignal thus obtained for sending to said radio transmission device; andsaid control units, given a presence of a voice signal transmitted bysaid radio reception device, transmitting a received signal to saidworkstations connected thereto and transferring said voice signals tosaid workstations; and a coupling unit connected to two or more saidcontrol units and/or superordinate control units, said coupling unit, onarrival of voice signals and of a received signal from a control unit orsuperordinate control unit connected thereto, forwarding the voicesignals and also an operator control signal to other control unitsand/or superordinate control units connected thereto.
 18. Thecommunication system according to claim 17, wherein said coupling unit,on simultaneous arrival of voice signals from two control units orsuperordinate control units connected thereto, selects one of saidcontrol units or superordinate control units according to prescribed orprescribable criteria and forwards only the voice signals of theselected said control unit or superordinate control unit to theremaining control units or superordinate control units connected to saidcoupling unit.
 19. The communication system according to claim 17,wherein: said coupling unit is configured to store criteria for theforwarding of data of individual control units or superordinate controlunits to other control units or superordinate control units; and saidcoupling unit is configured to transfer the voice signals arriving atsaid coupling unit to said control units or superordinate control unitsconnected thereto according to the criteria.
 20. The communicationsystem according to claim 17, further comprising a plurality ofdistribution units that are respectively associated with a workstation,wherein each workstation has at least one associated distribution unit,and wherein: between each of said distribution units and saidworkstation associated with said distribution unit there is respectivelya logical or physical data connection having a prescribed bandwidth thatcan be used to transfer voice signals from each voice input unit andvoice signals to each voice output unit of said workstation and alsooperator control signals and received signals; said distribution unitconfers or overlays the voice signals reaching it from radio receptiondevices according to a rule prescribed on the basis of control signalsand transmits the voice signals ascertained therefrom to the workstationor forwards the voice signals arriving from a selected radio receptiondevice to the workstation and, if there are actually voice signalspresent, forwards a received signal to the workstation; and saiddistribution unit transmits voice signals and operator control signalstransmitted to it by the workstation to radio transmission devicespreviously selected by way of control signals.